OBJECTIVES: 1. Determine quantitatively the amounts of pentane, ethane and ethylene that arise during iron-ascorbate or copper ascorbate catalyzed peroxidation or decomposition of preformed hydroperoxides of linoleic, linolenic and arachidonic acid. 2. Determine effectiveness of nonbiological antioxidants in the inhibition of the lipid peroxidation product pentane in rats fed a vitamin E-deficient diet. 3. Effects will be tested of feeding diets with 10% corn oil, 10% lard and 10% coconut oil as linoleic acid sources on the production of pentane in rats. Using pentane production as an index of lipid peroxidation, a vitamin E-deficient, 10% corn oil diet, will be fed to rats to determine the effects of feeding graded levels of selenium (0.01, 0.1 and 1 mg/kg) and also the effects of feeding rats diets supplemented with combinations of vitamin E and selenium. 4. To test for in vivo lipid peroxidation during chronic ingestion of ethanol, rats will be fed either a basal vitamin E and selenium-deficient diet or a vitamin E-selenium supplemented diet, and ethanol or saline will be given daily for a period of several weeks. Pentane production will be measured in exhaled breath over this time period. 5. Pentane will be measured for a period of days as an index of lipid peroxidation in rats following intubation or intraperitoneal injection of carbon tetrachloride. 6. The identification of fluorescent products in elastin and collagen will be completed. BIBLIOGRAPHIC REFERENCES: Taylor, S.L. and A.L. Tappel. Effect of dietary antioxidants and phenobarbital pretreatment on microsomal lipid peroxidation and activation by carbon tetrachloride. Life Sci. 19: 1151-1160 (1976). Dillard, C.J., E.E. Dumelin and A.L. Tappel. Effect of dietary vitamin E on expiration of pentane and ethane by the rat. Lipids 12: 109-114 (1977).